Electrolyte solution and sulfur-based or selenium-based batteries including the electrolyte solution

Abstract

An example of an electrolyte solution includes a solvent, a lithium salt, a fluorinated ether, and an additive. The additive is selected from the group consisting of RS x R′, wherein x ranges from 3 to 18, and R—(S n Se m )—R, wherein 2<n<8 and 2<m<8. R and R′ are each independently selected from a straight alkyl group having from 1 carbon to 6 carbons or branched alkyl group having from 1 carbon to 6 carbons. The electrolyte solution may be suitable for use in a sulfur-based battery or a selenium-based battery.

What is claimed is: 
     
       1. An electrolyte solution, comprising:
 a solvent; 
 a lithium salt; 
 a fluorinated ether; and 
 an additive represented by R—(S n Se m )—R, wherein 2<n<8 and 2<m<8, and wherein each R is independently selected from a straight or branched alkyl group having from 1 carbon to 6 carbons. 
 
     
     
       2. The electrolyte solution as defined in  claim 1  wherein the solvent is selected from the group consisting of 1,3-dioxolane, dimethoxyethane, and a mixture of 1,3-dioxolane and dimethoxyethane. 
     
     
       3. The electrolyte solution as defined in  claim 1  wherein the fluorinated ether is selected from the group consisting of bis(2,2,2-trifluoroethyl) ether (F 3 C—CH 2 —O—CH 2 —CF 3 ) and propyl 1,1,2,2-tetrafluoroethyl ether (H 7 C 3 —O—CF 2 —CHF 2 ). 
     
     
       4. The electrolyte solution as defined in  claim 1  wherein the lithium salt is selected from the group consisting of LiN(CF 3 SO 2 ) 2  (LiTFSI or lithium bis(trifluoromethylsulfonyl)imide), LiNO 3 , LiPF 6 , LiBF 4 , LiClO 4 , LiB(C 2 O 4 ) 2  (LiBOB), LiBF 2 (C 2 O 4 ) (LiODFB), LiN(SO 2 F) 2  (LiFSI), LiPF 3 (C 2 F 5 ) 3  (LiFAP), LiPF 4 (CF 3 ) 2 , LiPF 3 (CF 3 ) 3 , LiSO 3 CF 3 , LiAlCl 4 , LiI, LiBr, LiSCN, LiB(C 6 H 5 ) 4 , LiAsF 6 , LiCF 3 SO 3 , LiPF 4 (C 2 O 4 ) (LiFOP), and combinations thereof. 
     
     
       5. The electrolyte solution as defined in  claim 1  wherein a concentration of fluorinated ether in the electrolyte solution ranges from about 0.1 M to about 1 M, and a concentration of the additive in the electrolyte solution ranges from about 0.2 M to about 1 M. 
     
     
       6. The electrolyte solution as defined in  claim 1  wherein each R is a methyl group. 
     
     
       7. A sulfur-based battery, comprising:
 a negative electrode; 
 a positive electrode including a sulfur-based active material; 
 a separator positioned between the negative electrode and the positive electrode; and 
 an electrolyte solution soaking each of the positive electrode, the negative electrode, and the separator, wherein the electrolyte solution includes:
 a solvent; 
 a lithium salt; 
 a fluorinated ether; and 
 an additive represented by R—(S n Se m )—R, wherein 2<n<8 and 2<m<8, and wherein each R is independently selected from a straight or branched alkyl group having from 1 carbon to 6 carbons. 
 
 
     
     
       8. The sulfur-based battery as defined in  claim 7  wherein the negative electrode includes a silicon-based active material. 
     
     
       9. The sulfur-based battery as defined in  claim 7  wherein the negative electrode includes a lithium-based active material. 
     
     
       10. The sulfur-based battery as defined in  claim 7  wherein:
 the solvent is selected from the group consisting of 1,3-dioxolane, dimethoxyethane, and a mixture of 1,3-dioxolane and dimethoxyethane; 
 the fluorinated ether is selected from the group consisting of bis(2,2,2-trifluoroethyl) ether (F 3 C—CH 2 —O—CH 2 —CF 3 ) and propyl 1,1,2,2-tetrafluoroethyl ether (H 7 C 3 —O—CF 2 —CHF 2 ); and 
 the lithium salt is selected from the group consisting of LiN(CF 3 SO 2 ) 2  (LiTFSI or lithium bis(trifluoromethylsulfonyl)imide), LiNO 3 , LiPF 6 , LiBF 4 , LiClO 4 , LiB(C 2 O 4 ) 2  (LiBOB), LiBF 2 (C 2 O 4 ) (LiODFB), LiN(SO 2 F) 2  (LiFSI), LiPF 3 (C 2 F 5 ) 3  (LiFAP), LiPF 4 (CF 3 ) 2 , LiPF 3 (CF 3 ) 3 , LiSO 3 CF 3 , LiAlCl 4 , LiI, LiBr, LiSCN, LiB(C 6 H 5 ) 4 , LiAsF 6 , LiCF 3 SO 3 , LiPF 4 (C 2 O 4 ) (LiFOP), and combinations thereof. 
 
     
     
       11. The sulfur-based battery as defined in  claim 7  wherein a concentration of fluorinated ether in the electrolyte solution ranges from about 0.1 M to about 1 M, and a concentration of the additive in the electrolyte solution ranges from about 0.2 M to about 1 M. 
     
     
       12. The sulfur-based battery as defined in  claim 7  wherein each R is a methyl group. 
     
     
       13. A selenium-based battery, comprising:
 a negative electrode; 
 a positive electrode including a selenium-based active material; 
 a separator positioned between the negative electrode and the positive electrode; and 
 an electrolyte solution soaking each of the positive electrode, the negative electrode, and the separator, wherein the electrolyte solution comprises:
 a solvent; 
 a lithium salt; 
 a fluorinated ether; and 
 an additive represented by R—(S n Se m )—R, wherein 2<n<8 and 2<m<8, and wherein each R is independently selected from a straight or branched alkyl group having from 1 carbon to 6 carbons. 
 
 
     
     
       14. The selenium-based battery as defined in  claim 13  wherein the negative electrode includes an active material selected from the group consisting of graphite, a lithium-based active material, and a silicon-based active material. 
     
     
       15. The selenium-based battery as defined in  claim 13  wherein:
 the solvent is selected from the group consisting of 1,3-dioxolane, dimethoxyethane, and a mixture of 1,3-dioxolane and dimethoxyethane; 
 the fluorinated ether is selected from the group consisting of bis(2,2,2-trifluoroethyl) ether (F 3 C—CH 2 —O—CH 2 —CF 3 ) and propyl 1,1,2,2-tetrafluoroethyl ether (H 7 C 3 —O—CF 2 —CHF 2 ); and 
 the lithium salt is selected from the group consisting of LiN(CF 3 SO 2 ) 2  (LiTFSI or lithium bis(trifluoromethylsulfonyl)imide), LiNO 3 , LiPF 6 , LiBF 4 , LiClO 4 , LiB(C 2 O 4 ) 2  (LiBOB), LiBF 2 (C 2 O 4 ) (LiODFB), LiN(SO 2 F) 2  (LiFSI), LiPF 3 (C 2 F 5 ) 3  (LiFAP), LiPF 4 (CF 3 ) 2 , LiPF 3 (CF 3 ) 3 , LiSO 3 CF 3 , LiAlCl 4 , LiI, LiBr, LiSCN, LiB(C 6 H 5 ) 4 , LiAsF 6 , LiCF 3 SO 3 , LiPF 4 (C 2 O 4 ) (LiFOP), and combinations thereof.